Guy who assists a villain (8)

I believe the answer is:

henchman

(Other definitions for henchman that I've seen before include "abettor in crime?" , "Right-hand man" , "Accomplice" , "Faithful attendant" , "Follower of a criminal gang chief" .)

I've seen this clue in the Universal.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.